Effect of intravitreal injection of bevacizumab-chitosan nanoparticles on retina of diabetic rats

AIM:To investigate the effects of intravitreal injection of bevacizumab-chitosan nanoparticles on pathological morphology of retina and the expression of vascular endothelial growth factor(VEGF)protein and VEGF mRNA in the retina of diabetic rats.·METHODS:Seventy-two 3-month aged diabetic rats were randomly divided into 3 groups,each containing 24animals and 48 eyes.Both eyes of the rats in group A were injected into the vitreous at the pars plana with 3μL of physiological saline,while in groups B and C were injected with 3μL(75μg)of bevacizumab and 3μL of bevacizumab-chitosan nanoparticles(containing 75μg of bevacizumab),respectively.Immunohistochemistry was used to assess retinal angiogenesis,real-time PCR assay was used to analyze the expression of VEGF mRNA,and light microscopy was used to evaluate the morphology of retinal capillaries.·RESULTS:Real-time PCR assay revealed that the VEGF mRNA expression in the retina before injection was similar to 1 week after injection in group A(P】0.05),while the VEGF mRNA expression before injection significantly differed from those 4 and 8 weeks after injection(P【0.05).Retinal expression of VEGF protein and VEGF mRNA was inhibited 1 week and 4 weeks after injection(P【0.05)in group B,and the expression of VEGF protein and VEGF mRNA was obviously inhibited until 8 weeks after injection(P【0.05)in group C.Using multiple comparisons among group A,group B,and group C,the VEGF expression before injection was higher than at 1,4 and 8 weeks after injection(P【0.05).The amount of VEGF expression was higher 8 weeks after injection than 1 week or 4 weeks after injection,andalso higher 1 week after injection compared with 4 weeks after injection(P【0.05).No toxic effect on SD rats was observed with bevacizumab-chitosan nanoparticles injection alone.·CONCLUSION:The results offer a new approach for inhibiting angiogenesis of diabetic retinopathy and indicate that the intravitreal injection of bevacizumab inhibits VEGF expression in retina,and bevacizumabchitosan nanoparticles have a longer duration of action.

Panretinal photocoagulation versus panretinal photocoagulation plus intravitreal bevacizumab for high-risk proliferative diabetic retinopathy

AIM： To evaluate the effects of panretinal photocoagulation （PRP） compared with PRP plus intravitreal bevacizumab （IVB） in patients with high-risk proliferative diabetic retinopathy （PDR） according to the Early Treatment Diabetic Retinopathy Study criteria.METHODS： The data were collected retrospectively from the eyes of high-risk PDR patients, which were divided into two groups. After treated with standard PRP, the eyes were randomly assigned to receive only PRP （PRP group） or PRP plus intravitreal injection of 1.25 mg of bevacizumab （PRP-Plus group）. Patients underwent complete ophthalmic evaluation, including best corrected visual acuity （BCVA）, intraocular pressure （IOP）, and new vessel size in fluorescein angiography （FA） and optical coherence tomography for the assessment of central subfield macular thickness （CSMT） at baseline and at weeks 12 （±2）, 16 （±2）, 24 （±2） and 48 （±2）. Main outcome measures also included vitreous clear-up time and neovascularization on the disc （NVD） regression time. Adverse events associated with intravitreal injection were investigated.RESULTS： Thirty consecutive patients （n=36 eyes） completed the 48-week follow-up. There was no significant difference between the PRP and PRP-Plus groups with respect to age, gender, type or duration of diabetes, area of fluorescein leakage from active neovascularizations （NVs）, BCVA or CSMT at baseline. The mean vitreous clear-up time was 12.1±3.4wk after PRP and 8.4±3.5wk after PRP combined with IVB. The mean time interval from treatment to complete NVD regression on FA examination was 15.2±3.5wk in PRP group and 12.5±3.1wk in PRP-Plus group. No significant difference in CSMT was observed between the groups throughout the study period. However, the total area of actively leaking NVs was significantly reduced in the PRP-Plus group compared with the PRP group （P〈0.05）. Patients received an average of 1.3 injections （range： 1-2）. Ten eyes （27.8%） underwent 2 injections. Two eyes had ocular complication of PDR progression to dense vitreous hemorrhage （VH）. No major adverse events were identified.CONCLUSION： The adjunctive use of IVB with PRP is associated with a greater reduction in the area of active leaking NVs than PRP alone in patients with high-risk PDR. Short-term results suggest combined IVB and PRP achieved rapid clearance of VH and regression of retinal NV in the treatment of high-risk PDR. Further studies are needed to determine the effect of repeated intravitreal bevacizumab injections and the proper number of bevacizumab injections as an adjuvant.

Another Proliferative Diabetic Retinopathy? A Case Report of Retinal Cavernous Haemangioma Treated with Intravitreal Bevacizumab, Initially Labelled as Persistent Proliferative Diabetic Retinopathy

We present a case of Retinal Cavernous Haemangioma treated with Intravitreal Bevacizumab, which was initially labelled as persistent proliferative diabetic retinopathy with multiple episodes of vitreous haemorrhage. These lesions can be confused with new retinal vessels in diabetics and if correctly diagnosed unnecessary photocoagulation can be avoided. Our patient received a course of three intravitreal Bevacizumab injections (1.25 mg/0.05 ml) in order to stop the leakage from the retinal cavernous haemangioma lesions and prevent another episode of vitreous haemorrhage. No intraoperative or postoperative complications were seen. Twenty-two months following treatment there was no recurrence of vitreous haemorrhage.

Optimal timing of preoperative intravitreal anti-VEGF injection for proliferative diabetic retinopathy patients

AIM: To analyze concentrations of vascular endothelial growth factor(VEGF) and fibrosis-related factors in vitreous fluid of proliferative diabetic retinopathy(PDR) patients pretreated with intravitreal anti-VEGF injections(IVI) at different time periods prior to pars plana vitrectomy(PPV), and their correlation with the degree of vitreoretinal fibrosis and explore the optimal timing of preoperative IVI.METHODS: The prospective case-control study from January 2019 to July 2020 included 31 eyes with PDRrelated complications(PDR group) and 21 eyes with nondiabetic ocular disease(control group) requiring PPV. PDR eyes were divided into four groups based on timing of PPV: 3 d after IVI(3-day group);5 d after IVI(5-day group);7 or more days after IVI(≥7-day group);and no IVI. Vitreous fluid samples(0.5-1.0 m L) were collected prior to switching on the infusion before routine 23-G PPV. Concentrations of VEGF, basic fibroblast growth factor(b FGF), periostin(PN), interleukin(IL)-6, IL-8, and tumor necrosis factor(TNF)-α were measured by immunoassay, and concentration differences for each cytokine were compared among the groups. The degree of vitreoretinal fibrosis was graded intraoperatively, and the correlation between the changes in cytokine levels and the severity of vitreoretinal fibrosis was analyzed by univariate ordinal logistic regression analysis.RESULTS: PDR eyes without IVI had significantly higher VEGF, b FGF, PN, and IL-6 concentrations than nondiabetic eyes(all P<0.05), and had a significantly higher concentration of VEGF(P<0.05) and a significantly lower concentration of IL-8(P<0.05) than PDR eyes with IVI. Statistically significant differences were also observed for concentrations of VEGF, b FGF, PN, IL-6, and IL-8 among 3-day, 5-day, and ≥7-day groups(all P<0.05);meanwhile there was no significant difference in TNF-α among groups(P=0.226). The 5-day group had the lowest concentration of VEGF and the ≥7-day group had the highest concentration of b FGF and PN. The degree of vitreoretinal fibrosis was significantly higher in the ≥7-day group compared to the 3-day(P=0.015) and 5-day group(P=0.039), and vitreoretinal fibrosis correlated significantly with concentrations of b FGF, PN, IL-6, and IL-8(all P<0.05). Univariate ordinal logistic regression analysis showed that b FGF was an independent risk factor for the severity of vitreoretinal fibrosis in PDR patients pre-treated with IVI.CONCLUSION: The vitreous concentrations of VEGF, b FGF, PN, IL-6, and IL-8 change after pretreatment with IVI before PPV in PDR patients. The degree of vitreoretinal fibrosis is higher in patients with a longer time between IVI treatment and PPV, which may be related to the angiofibrosis switch. The results suggest that PPV should be performed 5 d after IVI administration in PDR patients.

Comparison of intravitreal bevacizumab with macular photocoagulation for treatment of diabetic macular edema: a systemic review and Meta-analysis

AIM: To further evaluate the efficacy and safety of intravitreal bevacizumab(IVB) versus macular photocoagulation(MPC) in treatment of diabetic macular edema(DME) by Meta-analysis. METHODS: Pertinent publications were identified through systemic searches of Pub Med, Medline,EMBASE, and the Cochrane Controlled Trials Register up to 30 November, 2013. Changes in central macular thickness(CMT) in μm and best-corrected visual acuity(BCVA) in log MAR equivalents were extracted at 1, 3, 6,12 and 24 mo after initial treatment, and a Meta-analysis was carried out to compare results between groups receiving IVB and MPC.RESULTS: Five randomized controlled trial(RCTs) and one high-quality comparative study were identified and included. Our Meta-analysis revealed that both IVB and MPC resulted in the improvements of CMT and BCVA in eyes with DME at 1mo after initial treatment, with IVB being significantly superior to MPC(P =0.01 and 0.02,respectively). The improvements of both measure outcomes at 3, 6, 12 and 24 mo after treatment did not vary significantly between the IVB groups and MPC groups(CMT at 3mo, P =0.85; at 6mo, P =0.29; at 12 mo,P =0.56; at 24 mo, P =0.71; BCVA at 3mo, P =0.31; at 6mo,P =0.30; at 12 mo, P =0.23; at 24 mo, P =0.52). However,the number of observed adverse events was low in all studies.CONCLUSION: Current evidence shows IVB treatment trends to be more effective in improvements of macular edema and vision in eyes with DME at an earlier follow up(1mo) compared with MPC. At other time, both interventions have comparable efficacy without statistical significances.

Improvement of visual acuity based on optical coherence tomography patterns following intravitreal bevacizumab treatment in patients with diabetic macular edema

AIMTo report the visual outcome based on various patterns of optical coherence tomography (OCT) morphology in diabetic macular edema (DME), following treatment with anti-VEGF intravitreal bevacizumab (IVB) injection.

Study of the Influence of Angiostatin Intravitreal Injection on Vascular Leakage in Retina and Iris of the Experimental Diabetic Rats

Purpose: To examine the effect of an intravitreal injection of angiostatin on vascular leakage in retina and iris of the diabetes and study its possible mechanism. Methods: Experimental diabetes was induced in 24 rats by an intravenous injection of streptozotocin (STZ) during 48 adult rats. Three groups were randomization distributed of them. There were 8 of both normal and diabetic rats in each group. STZ-diabetic rats and age-matched normal rats received an intravitreal injection of 5 μl of sterile PBS (Phosphate Buffered Saline) into the right eye, and the left eye was non-injected in the group A; Angiostatin was injected into the vitreous of the right eye (7.5 μg / 5 μl / eye), and the left eye received the same volume of sterile PBS as the control in the group B and C. The vascular permeability of retina and iris was measured using the Evans blue method at 2 days following the injection in the group A and B. Expression of VEGF in retina was evaluated using western blot analysis 24 hours following the injection in the group C. Results: Diabetic rats showed significant increases of vascular permeability in the retina ( P < 0.01) and iris ( P < 0.05). Angiostatin-injected eyes showed significant decreases in vascular permeability in the retina ( P < 0.01) and iris ( P < 0.05) comparing with the PBS-injected eyes in STZ-diabetic rats. In contrast, intravitreal injection of the same dose of angiostatin into the age-matched normal rats did not result in any significant reduction in vascular permeability in the retina and iris, when compared with the contralateral eye with PBS injection ( P > 0.05). Angiostatin injection significantly reduced VEGF level in the retinas of STZ-diabetic rats but did not affect retinal VEGF level in normal rats. Conclusions: Angiostatin significantly reduce pathological vascular permeability in the retina and iris of STZ-diabetic rats but not in normal rats. Angiostatin down-regulates VEGF expression and thus, blocks the major cause of vascular leakage in the diabetic retina. Therefore, angiostatin may have a therapeutic potential in the treatment of diabetic macular edema, cystoid macular edema, uvietis and other diseases with vascular leakage.

Comparison of structural outcome between intravitreal bevacizumab and laser treatment for type 1 retinopathy of prematurity after long-term follow-up

Background:To compare the structural outcome of intravitreal bevacizumab(IVB)and laser treatment for type 1 retinopathy of prematurity(ROP).Methods:This is a retrospective comparative study.From December 2002 to April 2009,patients with type 1ROP according to criteria of Early Treatment of Retinopathy of Prematurity(ETROP)study were treated by peripheral retinal diode laser photocoagulation in nearly confluent pattern.From May 2009 to January 2015,we performed IVB for patients with type 1 ROP.The patients were closely followed until disappearance of retinal neovascularization in the laser group and regression of avascular zone in the bevacizumab group.The demographical data,postmenstrual age(PMA)for treatment,and fundus findings were recorded by chart review.The difference between laser and bevacizumab groups was compared by Student t-test and Fisher exact test.Results:We collected 43 patients(86 eyes)with type 1 ROP,including 30 male and 13 female infants.Their mean gestation age and birth body weight(BBW)were 27.5 weeks and 1,034 gm.Zone I and zone II disease were found in 8 and 35 patients.The mean PMA for treatment was 37.3 weeks.The mean follow-up period was54.4 months.Laser treatment was administered in 26 patients,and bevacizumab injection for 17 infants.Single session of laser was performed in all patients of laser group without recurrence of retinal neovascularization.Complete regression of ROP was found in 15 infants of bevacizumab group following the first IVB.Four eyes in two patients(2/17,11.7%)had recurrence of ROP and received additional injections and adjuvant laser treatment.There was no unfavorable anatomical results such as retinal detachment or macular ectopia or complications such as cataract or endophthalmitis in either bevacizumab or laser management.Conclusions:Laser therapy and IVB were both effective treatments for type 1 ROP to cause favorable anatomical outcomes.Single session of laser ablation in nearly confluent pattern was sufficient for complete regression of ROP in laser group.Single IVB was appropriate for managing most of cases with ROP in bevacizumab group,but a small proportion(nearly one tenth)of them had recurrent episodes requiring adjuvant therapies.

Intravitreal aflibercept for rubeosis iridis secondary to proliferative diabetic retinopathy

The purpose of this article is to report a case with rubeosis iridis treated by intravitreal aflibercept. A 61-year-old man had iris neovascularization and scanty vitreous hemorrhage secondary to proliferative diabetic retinopathy in the right eye. Neither neovascularization of angle nor elevation of intraocular pressure was found. Single intravitreal al ibercept 2 mg injection was performed. Rubeosis iridis disappeared on the next day. Scattered retinal laser photocoagulation was added 1 week later. There was no recurrence after 3-month follow-up. Aflibercept may serve as another anti-vascular endothelial growth factor(anti-VEGF) for treating rubeosis iridis.

Perfluorocarbon in vitreoretinal surgery and preoperative bevacizumab in diabetic tractional retinal detachment

AIM: To describe the en bloc perfluorodissection(EBPD) technique and to demonstrate the applicabilityof using preoperative intravitreal bevacizumab duringsmall-gauge vitreoretinal surgery(23-gauge transconjunctival sutureless vitrectomy) in eyes with advancedproliferative diabetic retinopathy(PDR) with tractionalretinal detachment(TRD).METHODS: This is a prospective, interventional caseseries. Participants included 114(eyes) with advancedproliferative diabetic retinopathy and TRD. EBPD wasperformed in 114 eyes(consecutive patients) during23-gauge vitrectomy with the utilization of preoperativebevacizumab(1.25 mg/-0.05 mL). Patients mean age was 45 years(range, 21-85 years). Surgical time had a mean of 55 min(Range, 25-85 min). Mean follow up of this group of patients was 24 mo(range, 12-32 mo). Main outcome measures included best-corrected visual acuity(BCVA), retinal reattachment, and complications.RESULTS: Anatomic success occurred in 100%(114/-114) of eyes. Significant visual improvement [≥ 2 Early Treatment Diabetic Retinopathy Study(ETDRS) lines] was obtained in 69.2%(79/-114), in 26 eyes(22.8%) BCVA remained stable, and in 8 eyes(7%) BCVA decreased(≥ 2 ETDRS lines). Final BCVA was 20/-50 or better in 24% of eyes, between 20/-60 and 20/-400 in 46% of eyes, and worse than 20/-400 in 30% of eyes. Complications included cataract in 32(28%) eyes, iatrogenic retinal breaks in 9(7.8%) eyes, vitreous hemorrhage requiring another procedure in 7(6.1%) eyes, and phthisis bulbi in 1(0.9%) eye.CONCLUSION: This study demonstrates the usefulne-ss of using preoperative intravitreal bevacizumab and EBPD during smallgauge vitreoretinal surgery in eyes with TRD in PDR.

Bevacizumab treatment reduces retinal neovascularization in a mouse model of retinopathy of prematurity

·AIM: To evaluate the effect of different bevacizumab concentrations on retinal neovascularization in a retinopathy of prematurity(ROP) mouse model.·METHODS: A total of 60 of C57BL/6 J mice were exposed to 75% ±2% oxygen from postnatal d7 to postnatal d12. Fifteen nonexposed mice served as negative controls(group A). On d12, 30 mice(group C)were injected with 2.5 μg intravitreal bevacizumab(IVB),30 mice(group D) were injected with 1.25 μg IVB in one eye. The contralateral eyes were injected with balanced salt solution(BSS)(control group =group B). The adenosine diphosphatase(ADPase) histochemical technique was used for retinal flat mount to assess the oxygen-induced changes of retinal vessels.Neovascularization was quantified by counting the endothelial cell proliferation on the vitreal side of the inner limiting membrane of the retina. Histological changes were examined by light microscopy. The mRNA levels of vascular endothelial growth factor(VEGF) were quantified by Real-time PCR. Western-blotting analysis was performed to examine the expression of P-VEGFR.· RESULTS: Comparing with the control group B,regular distributions and reduced tortuosity of vessels were observed in our retinal flat mounts in groups C and D. The endothelial cell count per histological section was lower in groups C(P 【0.0001) and D(P 【0.0001) compared with the control group B. Histological evaluation showed no retinal toxicity in any group. In all oxygen treated groups VEGF mRNA expression was significantly increased as compared to age-matched controls. No significant change in VEGF mRNA expression could be achieved in either of the treatments or the oxygen controls. The results of the Western blot were consistent with that of the Real-time PCR analysis.·CONCLUSION: An intravitreal injection of bevacizumab is able to reduce angioproliferative retinopathy in a mouse model for oxygen-induced retinopathy.

Bevacizumab在早产儿视网膜病变治疗中的应用研究进展

无论在发展中国家还是在发达国家,早产儿视网膜病变(retinopathy of prematurity,ROP)都是小儿致盲的主要原因。预防ROP失明的关键在于及时发现阈值或阈值前病变,并在"时间窗"内进行冷凝或光凝治疗,尽管如此,仍有部分患眼会发展到4期、5期ROP。4期、5期ROP术后解剖结构和视力的预后都不容乐观。因此,ROP的治疗方法仍有待进一步发展,近年来有报道用玻璃体腔注射Bevacizumab治疗ROP,取得了一定的疗效。本文就Bevacizumab在ROP治疗中的应用进展进行扼要综述。

玻璃体腔注射Bevacizumab治疗糖尿病黄斑水肿的疗效观察

目的观察玻璃体腔注射Bevacizumab治疗糖尿病黄斑水肿的临床疗效。方法 65例（66眼）糖尿病黄斑水肿患者初始均行玻璃体腔注射Bevacizumab治疗,观察患眼治疗前、后最佳矫正视力、黄斑水肿分级、黄斑水肿渗漏类型及黄斑中心视网膜厚度和黄斑总体积的变化情况。对其中前3个月内仅接受单次玻璃体腔注射Bevacizumab治疗的38例（41眼）患者治疗前、治疗后2周、6周和12周的各项指标进一步进行统计分析。结果 65例（66眼）DME患者治疗前平均最佳矫正视力字母数、平均黄斑中心视网膜厚度和黄斑总体积分别为39.81±17.18、（514.11±247.43）μm和（11.70±2.37）mm3,末次随访时分别为43.45±14.38、（455.47±193.34）μm和（10.64±2.13）mm3。其中前3个月内进行单次玻璃体腔注射Bevacizumab治疗的38例（41眼）患者治疗前平均最佳矫正视力字母数为45.09±12.68,治疗后2周、6周和12周时分别为52.45±13.67、59.09±12.31和50.36±11.72,治疗后视力明显提高,与治疗前相比差异均有统计学意义（均为P〈0.05）;平均黄斑中心视网膜厚度治疗前为（503.95±246.79）μm,治疗后2周、6周和12周分别为（348.91±209.76）μm、（327.93±127.60）μm和（444.00±193.61）μm,治疗后厚度明显变薄,与治疗前相比差异均有统计学意义（均为P〈0.05）;治疗前黄斑总体积为（11.07±2.23）mm3,治疗后2周、6周和12周时分别为（10.25±1.81）mm3、（9.76±2.01）mm3和（9.92±1.49）mm3,治疗后体积缩小,与治疗前相比差异均无统计学意义（均为P〉0.05）。所有患者随访期间均未见明显严重不良事件发生。结论玻璃体腔注射Bev-acizumab可减轻糖尿病黄斑水肿患者视网膜水肿程度,提高患眼视力,但疗效持续时间有限,单次注射疗效约可维持812周。其长期有效性和安全性仍有待多中心临床试验验证。

Bevacizumab治疗糖尿病黄斑水肿的现状

糖尿病黄斑水肿(DME)是导致糖尿病视网膜病变患者视力降低的主要原因,除了严格控制血糖和血压以外,目前,治疗DME的主要方法包括黄斑部激光光凝、玻璃体腔注射曲安奈德和/或抗血管内皮生长因子(VEGF)药物以及玻璃体切除手术等,对于复杂的难治性DME常常需要以上两种或三种方法的联合治疗。近年来,随着抗VEGF药物的出现,使DME的治疗出现了新希望,其中Bevacizumab因其较强的可用性和合理的费用而得到广泛应用,大量的研究已证实其治疗的有效性和安全性。本文综述了近两年具有A级和B级循证医学证据的、有关Bevacizumab治疗DME的文献。

Diabetic retinopathy:A review on its pathophysiology and novel treatment modalities

Diabetes mellitus(DM)is a chronic metabolic non-communicable disease with the ability to cause serious microvascular and macrovascular complications throughout the body,including in the eye.Diabetic retinopathy(DR),present in onethird of patients with diabetes,is a vision-threatening complication caused by uncontrolled diabetes,which greatly affects the retinal blood vessels and the lightsensitive inner retina,eventually leading to blindness.Several epidemiological studies elucidate that DR can vary by age of onset,duration,types of diabetes,and ethnicity.Recent studies show that the pathogenesis of diabetic retinopathy has spread its roots beyond merely being the result of hyperglycemia.The complexity of its etiopathology and diagnosis makes therapeutic intervention challenging.This review throws light on the pathological processes behind DR,the cascade of events that follow it,as well as the available and emerging treatment options.

玻璃体注射Bevacizumab治疗26例Ⅰ区早产儿视网膜病变

目的:评价玻璃体注射bevacizumab治疗26例Ⅰ区早产儿视网膜病变(retinopathy of prematurity,ROP)的治疗效果。方法:通过回顾性研究,对2013-09/2014-10确诊为Ⅰ区阈值期ROP并行玻璃体注射bevacizumab治疗的26例患儿分三组(阈值前期Ⅰ型ROP、阈值期ROP、急进型后极部早产儿视网膜病变-APROP),进行术后效果分析比较。结果:治疗Ⅰ区高危性阈值期ROP患儿26例52眼。其中阈值前期Ⅰ型ROP 3例6眼,阈值期ROP 15例30眼,APROP 8例16眼。治疗阈值期Ⅰ型ROP、阈值期ROP和APROP的一次手术治愈率分别为100%(6/6)、60%(18/30)和75%(12/16),三组之间手术治愈率无统计学差异(P>0.05)。结论:玻璃体腔内注射bevacizumab治疗Ⅰ区ROP的临床疗效明确,比传统光凝术治疗具有一定优越性,可作为I区ROP的一线治疗方法。

Intravitreal bevacizumab with or without triamcinolone acetonide for diabetic macular edema： a meta-analysis of randomized controlled trials

Background Intravitreal anti-vascular endothelial growth factor （anti-VEGF） drugs and corticosteroids are being widely used to treat diabetic macular edema （DME）. The purpose of this study was to evaluate further the efficacy and safety of intravitreal bevacizumab （IVB） alone in comparison with intravitreal bevacizumab combined with triamcinolone acetonide （IVB/IVT） in the treatment of DME. Methods Pertinent publications were identified through CNKI, PubMed, Medline, EMBASE, and the Cochrane Controlled Trials Register up to November 30, 2013. Two investigators independently assessed the quality of the trials, and changes in central macular thickness （CMT） and best-corrected visual acuity （BCVA） were extracted at 6 weeks and 3, 6, 12, and 24 months after the initial treatment. A meta-analysis was carried out to compare the results between the groups receiving IVB and IVB/IVT using the software RevMan 5.0. Results A total of six randomized controlled trials （RCTs） were identified and included. The meta-analysis revealed that a significant reduction of the CMT was observed at 3 months after the initial treatment in the IVB/IVT group compared to the IVB group （P=-0.001）. Also, changes in CMT at 6 weeks and 6, 12, and 24 months did not vary significantly between the IVB and IVB/IVT groups （P=0.53, 0.76, 0.34, and 0.09, respectively）. Similarly, changes in BCVA at 6 weeks and 3, 6, 12, and 24 months also did not vary significantly between the two groups （P=-0.66, 0.98, 0.81, 0.07, and 0.80, respectively）. The results were robust to sensitivity analyses. However, the rate of intraocular pressure （IOP） rise after intravitreal injections varied significantly between the IVB and IVB/IV＇r groups （P 〈0.01）. A publication bias was not detected by funnel plots, the Egger method, or the Begg method. Conclusions Results of this meta-analysis showed that the treatments with IVB alone and combined IVB/IVT were similarly effective in improving the visual acuity, and, to some degree; combined IVB/IVT appeared to offer a marginal advantage over IVB in decreasing CMT in patients with DME. However, the addition of IV＇I- resulted in intraocular pressure rise in some treated patients.

Pharmacological adjuvants for diabetic vitrectomy surgery

Diabetic vitrectomy is a highly intricate surgical procedure performed during the advanced stages of diabetic retinopathy(DR).It is used to treat conditions such as tractional or combined retinal detachment,vitreous hemorrhage,and subhyaloid hemorrhage,which are all severe manifestations of proliferative DR.The results of the surgery are uncertain and variable.Vitreoretinal surgery has made significant progress since the early stages of vitrectomy.In the past ten years,advancements in intravitreal pharmacotherapy have emerged,offering new possibilities to improve the surgical results for our patients.Within the realm of medical terminology,an"adjunct"refers to a pharmaceutical or substance employed to aid or expedite the primary therapeutic intervention for a particular ailment.Their introduction has broadened the range of therapeutic choices that are accessible prior to,during,and following surgical procedures.This review article will specifically analyze the pharmacological adjuncts used in diabetic vitrectomy surgery,with a focus on their role in facilitating or aiding specific steps of the procedure.The implementation of this system of categorization offers benefits to the surgeon by allowing them to foresee potential difficulties that may occur during the surgical procedure and to choose the appropriate pharmacological agent to effectively tackle these challenges,thus enhancing surgical success rates.

Diabetic retinopathy-ocular complications of diabetes mellitus

In industrialized nations diabetic retinopathy is the most frequent microvascular complication of diabetes mellitus and the most common cause of blindness in the workingage population.In the next 15 years,the number of patients suffering from diabetes mellitus is expected to increase significantly.By the year 2030,about 440 million people in the age-group 20-79 years are estimated to be suffering from diabetes mellitus worldwide(prevalence 7.7%),while in 2010 there were 285 million people with diabetes mellitus(prevalence 6.4%).This accounts for an increase in patients with diabetes in industrializednations by 20% and in developing countries by 69% until the year 2030.Due to the expected rise in diabetic patients,the need for ophthalmic care of patients(i.e.,exams and treatments) will also increase and represents a challenge for eye-care providers.Development of optimized screening programs,which respect available resources of the ophthalmic infrastructure,will become even more important.Main reasons for loss of vision in patients with diabetes mellitus are diabetic macular edema and proliferative diabetic retinopathy.Incidence or progression of these potentially blinding complications can be greatly reduced by adequate control of blood glucose and blood pressure levels.Additionally,regular ophthalmic exams are mandatory for detecting ocular complications and initiating treatments such as laser photocoagulation in case of clinical significant diabetic macular edema or early proliferative diabetic retinopathy.In this way,the risk of blindness can considerably be reduced.In advanced stages of diabetic retinopathy,pars-plana vitrectomy is performed to treat vitreous hemorrhage and tractional retinal detachment.In recent years,the advent of intravitreal medication has improved therapeutic options for patients with advanced diabetic macular edema.

玻璃体腔注射抗血管内皮生长因子、全视网膜激光光凝术先后应用顺序不同治疗重度非增殖期糖尿病视网膜病变的效果比较

目的:评价玻璃体腔注射抗血管内皮生长因子(VEGF)、全视网膜激光光凝术(PRP)先后应用顺序不同治疗重度非增殖期糖尿病视网膜病变的临床效果。方法:选取2020年1月—2021年12月中山大学附属第五医院收治的41例(72眼)重度非增殖期糖尿病视网膜病变患者作为研究对象,随机分为顺序1组21例(33眼),顺序2组20例(39眼)。顺序1组采用连续3次玻璃体腔内注射抗VEGF治疗后进行PRP,顺序2组完成PRP后连续3次玻璃体腔内注射抗VEGF治疗。比较两组最佳矫正视力(BCVA)和黄斑中心凹视网膜厚度(CMT)。结果:治疗后3、6、9、12个月,两组BCVA低于治疗前,且治疗后6、9、12个月,顺序1组BCVA低于顺序2组,差异有统计学意义(P<0.05)。治疗后3、6、9、12个月,两组CMT逐渐降低,且治疗后6、9、12个月,顺序1组CMT低于顺序2组,差异有统计学意义(P<0.05)。结论:玻璃体腔注射抗VEGF、PRP先后应用顺序不同均能有效治疗重度非增殖期糖尿病视网膜病变,但是先应用玻璃体腔注射抗VEGF,后行PRP治疗的BCVA更低,视力改善更佳,CMT下降更明显。